Many swimming pools are often covered during part of the year. Many swimming pool covers are quite strong, but since most of the popular swimming pool covers are flexible, and many swimming pools are large, there is a tendency for the pool cover to sag within the perimeter of the pool. Water then tends to collect or accumulate in the lower portions of the sagging pool cover. Since water is heavy, if water is permitted to accumulate undrained from the pool cover, even the strongest cover can be damaged by a large accumulation of water.
Many pool owners and attendants remove accumulated water by hand, but this becomes an onerous task, and may even be impractical if the owner is away from the pool for an extended period of time.
Accordingly, there have been various swimming pool cover drain means proposed to automatically drain accumulated water from swimming pool covers. An example of such an automatic swimming pool cover drain is disclosed in U.S. Pat. No. 4,318,421 issued to Geoffrey A. Ward on Mar. 9, 1982.
While effective for the purpose of automatically draining water from a swimming pool cover and accounting for foreign matter in that water, the Ward device may still have the siphon action broken if the discharge opening is not properly closed. If the siphon action is broken, the Ward device will not operate until the siphon hose is refilled. This refilling may require manual attention thereby vitiating some of the advantages of this device.
While the Ward device attempts to prevent the breaking of the siphon, it may not be able to fully protect against the possibility that the drain opening may not be closed quickly enough to prevent the breaking of the siphon action prior to the drain opening being properly occluded by the closing plug device of the mechanism.
Still further, since the Ward device, like other siphon devices, operates in water and is thus subject to corrosion. The Ward device is specifically disclosed as operating in water with foreign objects therein. Accordingly, the Ward device may be subject to having the float jam or otherwise not operate properly. In the case the float does not operate properly, the drain may not be closed by action of the float, and the siphon broken due to such malfunctioning float.
While other float operated siphon devices are known, none has elements that permit a float controlled swimming pool cover siphon discharge valve to operate quickly and fully automatically, even in the event that the water level in the reservoir of water being drained drops below a level that might break the siphon action prior to the occluding of the drain opening.
Accordingly, there is need for a swimming pool cover drain mechanism that is fully automatic, and has the ability to effectively preclude the possibility of breaking the siphon action prior to the closing of a drain valve.